全文获取类型
收费全文 | 46124篇 |
免费 | 3632篇 |
国内免费 | 1059篇 |
专业分类
耳鼻咽喉 | 270篇 |
儿科学 | 918篇 |
妇产科学 | 1353篇 |
基础医学 | 4371篇 |
口腔科学 | 842篇 |
临床医学 | 5136篇 |
内科学 | 6951篇 |
皮肤病学 | 270篇 |
神经病学 | 1785篇 |
特种医学 | 1643篇 |
外国民族医学 | 9篇 |
外科学 | 3839篇 |
综合类 | 7327篇 |
现状与发展 | 1篇 |
预防医学 | 6910篇 |
眼科学 | 437篇 |
药学 | 5122篇 |
100篇 | |
中国医学 | 1773篇 |
肿瘤学 | 1758篇 |
出版年
2023年 | 593篇 |
2022年 | 946篇 |
2021年 | 1734篇 |
2020年 | 1730篇 |
2019年 | 1486篇 |
2018年 | 1531篇 |
2017年 | 1478篇 |
2016年 | 1581篇 |
2015年 | 1507篇 |
2014年 | 3048篇 |
2013年 | 3188篇 |
2012年 | 2873篇 |
2011年 | 3106篇 |
2010年 | 2352篇 |
2009年 | 2152篇 |
2008年 | 2119篇 |
2007年 | 2247篇 |
2006年 | 1830篇 |
2005年 | 1646篇 |
2004年 | 1420篇 |
2003年 | 1188篇 |
2002年 | 1074篇 |
2001年 | 955篇 |
2000年 | 833篇 |
1999年 | 756篇 |
1998年 | 589篇 |
1997年 | 615篇 |
1996年 | 587篇 |
1995年 | 529篇 |
1994年 | 515篇 |
1993年 | 395篇 |
1992年 | 429篇 |
1991年 | 386篇 |
1990年 | 323篇 |
1989年 | 320篇 |
1988年 | 270篇 |
1987年 | 227篇 |
1986年 | 199篇 |
1985年 | 270篇 |
1984年 | 235篇 |
1983年 | 151篇 |
1982年 | 195篇 |
1981年 | 173篇 |
1980年 | 160篇 |
1979年 | 138篇 |
1978年 | 117篇 |
1977年 | 106篇 |
1976年 | 96篇 |
1975年 | 96篇 |
1974年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
《Vaccine》2022,40(24):3380-3388
BackgroundWe evaluated the safety and immunogenicity of NVX-CoV2373, a recombinant SARS-CoV-2 nanoparticle vaccine, in healthy Japanese participants.MethodsThis phase 1/2, randomized, observer-blind, placebo-controlled trial conducted in Japan (two sites), enrolled healthy Japanese adults aged ≥ 20 years with no history/risk of SARS-CoV-2 infection and no prior exposure to other approved/investigational SARS-CoV-2 vaccines or treatments. Participants were stratified by age (< 65 or ≥ 65 years) and randomized to receive two doses of either NVX-CoV2373 (5 μg SARS-CoV-2 rS; 50 μg Matrix-M1) or placebo, 21 days apart. Primary outcomes were safety and immunogenicity assessed by serum IgG antibody levels against SARS-CoV-2 rS protein on day 36. Herein, we report the primary data analysis at 4 weeks after the second dose, ahead of 12-month follow-up completion (data cut-off: 8 May 2021).ResultsBetween 12 February 2021 and 17 March 2021, 326 subjects were screened, and 200 participants enrolled and randomized: NVX-CoV2373, n = 150; placebo, n = 50. Solicited adverse events (AEs) through 7 days after each injection occurred in 121/150 (80.7%) and 11/50 (22.0%) participants in the NVX-CoV2373 and placebo arms, respectively. In the NVX-CoV2373 arm, tenderness and injection site pain were the most frequently reported solicited AEs after each vaccination, irrespective of age. Robust immune responses occurred with NVX-CoV2373 (n = 150) by day 36: IgG geometric mean fold rise (95% confidence interval) 259 (219, 306); seroconversion rate 100% (97.6, 100). No such response occurred with placebo (n = 49).ConclusionTwo doses of NVX-CoV2373 given with a 21-day interval demonstrated acceptable safety and induced robust anti-SARS-CoV-2 immune responses in healthy Japanese adults. Funding: Takeda Pharmaceutical Company Limited and Japan Agency for Medical Research and Development (AMED). ClinicalTrials.gov identifier: NCT04712110. 相似文献
32.
Silvia Ceccanti Francesco Cozzi Alice Cervellone Augusto Zani Denis A. Cozzi 《Journal of pediatric surgery》2019,54(2):326-330
Aim
We sought to assess the magnitude of functional decline and the natural history of the operated kidney residual function after zero-ischemia nephron-sparing surgery (Z-NSS) in children with unilateral renal tumor (URT).Patients and methods
50 children were treated for URT at our surgical unit between 1992 and 2016. Of these 12 who underwent Z-NSS were available for the current analysis. Operated kidney function was assessed by 99mTc-dimercapto-succinic acid (DMSA) renal scintigraphy. Operated kidney volume was assessed by renal ultrasonography.Results
A positive correlation between split renal function and split renal volume was found (P?=?0.001). The subset of patients with ≥ 40% preservation of operated kidney function/volume (OKF/V) had no-time dependent changes during adolescence. The subset of patients with < 40% OKF/V preservation had a catch-up growth that after puberty reached values not much different from those with ≥ 40% OKF/V preservation. At 5?years of follow-up, 3 of 5 patients with baseline dysfunction (eGFR between 40.8 and 89.4?ml/min/1.73?m2) presented with a global renal function within normal range. After puberty, all patients presented with global renal function within normal values (eGFR between 95 and 151?ml/min/1.73 m2).Conclusions
In children with URT who underwent Z-NSS, the pattern of OKF/V recovery suggests that compensatory catch-up growth capacity during childhood minimizes OKF/V decline more than Z-NSS.Level of evidence
Level I prognosis study — prospective cohort study with > 80% follow-up and all patients enrolled at same time point in disease. 相似文献33.
Marginal rate-based analyses are widely used for the analysis of recurrent events in clinical trials. In many areas of application, the events are not instantaneous but rather signal the onset of a symptomatic episode representing a recurrent infection, respiratory exacerbation, or bout of acute depression. In rate-based analyses, it is unclear how to best handle the time during which individuals are experiencing symptoms and hence are not at risk. We derive the limiting value of the Nelson-Aalen estimator and estimators of the regression coefficients under a semiparametric rate-based model in terms of an underlying two-state process. We investigate the impact of the distribution of the episode durations, heterogeneity, and dependence on the asymptotic and finite sample properties of standard estimators. We also consider the impact of these features on power in trials designed to test intervention effects on rate functions. An application to a trial of individuals with herpes simplex virus is given for illustration. 相似文献
34.
35.
《Journal of vascular and interventional radiology : JVIR》2019,30(8):1265-1272
PurposeTo evaluate the safety and efficacy of balloon pulmonary angioplasty (BPA) for nonoperable chronic thromboembolic pulmonary hypertension (CTEPH) patients during the initial experience of a single center.MethodsA total of 18 CTEPH patients (5 with residual pulmonary hypertension after pulmonary endarterectomy) were treated with BPA during the period 2014–2018 and were retrospectively reviewed. Mean age was 61 ± 19 years; 55% were female; mean pulmonary artery pressure was 44 ± 12 mmHg; cardiac output was 4.3 ± 1.0 l/min; and pulmonary vascular resistance was 8.4 ± 3.6 WU. Patients were evaluated by New York Heart Association functional class, 6-minute walk distance, N-terminal pro b-type natriuretic peptide, echocardiography, right heart catheterization, and before and after completions of BPA.ResultsA total of 91 procedures were performed, with a median number of 4 BPA sessions per patient (range, 2–8). There were no deaths or major complications requiring extracorporeal support or (non)invasive ventilation. The most common complication was self-limiting hemoptysis (3%). According to Society of Interventional Radiology classification, 4 mild, 4 moderate, and 1 severe adverse events were noted. Invasive hemodynamics significantly improved, with a cardiac index increase of 15% (P = .0333), decrease of mean pulmonary artery pressure of 30% (P = .0013), and decrease of pulmonary vascular resistance of 45% (P = .0048). Stroke volume index (P = .0171) and pulmonary arterial compliance (P = .0004) were also significantly enhanced.ConclusionsBPA significantly improves cardiopulmonary hemodynamics with an acceptable safety profile. Further studies assessing the long-term efficacy of BPA are required. 相似文献
36.
37.
Rika Yoshimatsu Takuji Yamagami Miki Nishimori Kenta Ogi Yoriko Murata Hitomi Iwasa Kenji Kajiwara Tomoaki Yamanishi Hiroki Minamiguchi Takashi Karashima Keiji Inoue 《Journal of vascular and interventional radiology : JVIR》2019,30(3):460-465
Purpose
To evaluate the influence of percutaneous cryoablation for renal cell carcinoma on function of the affected kidney.Materials and Methods
Between June 2016 and September 2017 at our institution, 12 inoperable patients underwent 15 cryoablation sessions for 17 small renal tumors. Of these, 9 patients who underwent 11 sessions of cryoablation were the focus of this study. For those patients, time-dependent changes in postoperative renal function were investigated by a retrospective review of clinical records. Evaluated were the estimated glomerular filtration rate (eGFR) and scintigraphy using 99m technetium-mercaptoacetyltriglycine (99mTc-MAG3) before and 1 week, 1–2 months, and more than 6 months after cryoablation.Results
Mean baseline eGFR was 76.88 ± 29.82 mL/min/1.73 m2 (mean ± standard deviation; range, 23.4–112.5). Mean eGFR 1 week, 1–2 months, and more than 6 months after cryoablation were 74.56 ± 26.68 mL/min/1.73 m2 (21.0–101.1), 69.5 ± 25.28 mL/min/1.73 m2 (24.1–105.6), and 75.08 ± 26.25 mL/min/1.73 m2 (29.0–107.3), respectively. Changes were statistically insignificant (P = .6044, P = .6699, and P = .9038, respectively). Regarding split renal function, the mean baseline contribution of the affected kidney determined by 99mTc-MAG3 was 47.27% ± 6.14 (38.8%–57.0%). Mean contributions of the affected kidney 1 week after, 1–2 months after, and more than 6 months after cryoablation were 44.40% ± 5.37 (38.3%–53.6%), 44.57% ± 6.52 (34.35%–55.0%), and 45.41% ± 7.77 (34.4%–56.5%), respectively. Differences from baseline were significant for the earliest 2 periods (P = .0473 and P = .0334, respectively) but not the later period (P = .2532).Conclusions
Results suggested that total renal function does not worsen after cryoablation; however, function of the affected kidney worsened after cryoablation but later partially recovered. 相似文献38.
目的了解汶川地震9年后广元地区高二学生创伤后应激障碍(PTSD)阳性检出情况,为进一步分析震后PTSD持续存在的影响因素、对存在PTSD的学生进行心理干预提供参考。方法采用整群抽样方法,选取广元地区地震重灾区和一般灾区的1 492名高二学生为研究对象。采用创伤后应激障碍自评量表(PTSD-SS)和社会支持量表(PSSS)调查PTSD发生率和社会支持情况。结果广元地区高二学生PTSD阳性检出率为3.69%,男生和女生PTSD阳性检出率比较差异有统计学意义(2.24%vs. 5.82%,χ~2=12.47,P0.01),重灾区和一般灾区PTSD阳性检出率比较差异有统计学意义(4.89%vs. 2.84%,χ~2=4.27,P0.05);男生和女生PTSD-SS评分比较差异有统计学意义[(12.71±9.01)分vs.(14.02±8.52)分,t=-6.43,P0.01];PTSD阳性者和非阳性者PSSS评分比较差异有统计学意义[(57.52±7.53)分vs.(61.11±8.19)分,t=-5.36,P0.01]。结论汶川地震后9年,广元地区部分高二学生仍存在PTSD症状,创伤暴露程度、性别和社会支持可能与现患PTSD相关。 相似文献
39.
40.
Alison Connolly Kate Jones Ioannis Basinas Karen S. Galea Laura Kenny Padraic McGowan Marie A. Coggins 《International journal of hygiene and environmental health》2019,222(2):205-210